Note 9. Debt Components and Fair Value of Debt (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023
Debt Instrument [Line Items]
Debt, Long-Term and Short-Term, Combined Amount	$ 5,690.9	$ 5,754.2
Long-term Debt, Fair Value	5,593.0	5,542.3
Recourse
Debt Instrument [Line Items]
Debt, Long-Term and Short-Term, Combined Amount	597.8	794.6
Nonrecourse
Debt Instrument [Line Items]
Debt, Long-Term and Short-Term, Combined Amount	5,093.1	4,959.6
Corporate Segment [Member]
Debt Instrument [Line Items]
Debt, Net of Unamortized Discount and Premium, Gross of Unamortized Debt Issuance Costs	604.3	799.9
Unamortized Debt Issuance Expense	6.5	5.3
Long-term Debt, Fair Value	623.2	812.1
Corporate Segment [Member] | Recourse
Debt Instrument [Line Items]
Debt, Long-Term and Short-Term, Combined Amount	597.8	794.6
Wholly Owned Subsidiaries [Member] | Nonrecourse
Debt Instrument [Line Items]
Debt, Long-Term and Short-Term, Combined Amount	4,021.3	3,819.2
Wholly Owned Subsidiaries [Member] | Railcar Leasing and Services Group [Member]
Debt Instrument [Line Items]
Debt, Net of Unamortized Discount and Premium, Gross of Unamortized Debt Issuance Costs	4,036.6	3,836.5
Unamortized Debt Issuance Expense	15.3	17.3
Long-term Debt, Fair Value	3,950.8	3,686.2
Wholly Owned Subsidiaries [Member] | Railcar Leasing and Services Group [Member] | Nonrecourse
Debt Instrument [Line Items]
Debt, Long-Term and Short-Term, Combined Amount	4,021.3	3,819.2
Partially-Owned Subsidiaries [Member] | Nonrecourse
Debt Instrument [Line Items]
Debt, Long-Term and Short-Term, Combined Amount	1,071.8	1,140.4
Partially-Owned Subsidiaries [Member] | Railcar Leasing and Services Group [Member]
Debt Instrument [Line Items]
Debt, Net of Unamortized Discount and Premium, Gross of Unamortized Debt Issuance Costs	1,076.8	1,147.8
Unamortized Debt Issuance Expense	5.0	7.4
Long-term Debt, Fair Value	1,019.0	1,044.0
Partially-Owned Subsidiaries [Member] | Railcar Leasing and Services Group [Member] | Nonrecourse
Debt Instrument [Line Items]
Debt, Long-Term and Short-Term, Combined Amount	1,071.8	1,140.4
2009 Secured Railcar Equipment Notes [Member] | Wholly Owned Subsidiaries [Member] | Railcar Leasing and Services Group [Member]
Debt Instrument [Line Items]
Non-Recourse Debt, Gross	0.0	99.7
Long-term Debt, Fair Value	0.0	100.3
2010 Secured Railcar Equipment Notes [Member] | Wholly Owned Subsidiaries [Member] | Railcar Leasing and Services Group [Member]
Debt Instrument [Line Items]
Non-Recourse Debt, Gross	150.0	181.2
Long-term Debt, Fair Value	148.5	176.5
2018 Secured Railcar Equipment Notes [Domain] | Wholly Owned Subsidiaries [Member] | Railcar Leasing and Services Group [Member]
Debt Instrument [Line Items]
Debt, Net of Unamortized Discount and Premium, Gross of Unamortized Debt Issuance Costs	359.1	378.0
Debt Instrument, Unamortized Discount	(0.1)	(0.1)
Long-term Debt, Fair Value	344.9	355.2
2019 Secured Railcar Equipment Notes [Domain] | Wholly Owned Subsidiaries [Member] | Railcar Leasing and Services Group [Member]
Debt Instrument [Line Items]
Debt, Net of Unamortized Discount and Premium, Gross of Unamortized Debt Issuance Costs	711.3	748.5
Debt Instrument, Unamortized Discount	(0.1)	(0.1)
Long-term Debt, Fair Value	694.7	709.4
2020 Secured Railcar Equipment Notes [Domain] | Wholly Owned Subsidiaries [Member] | Railcar Leasing and Services Group [Member]
Debt Instrument [Line Items]
Debt, Net of Unamortized Discount and Premium, Gross of Unamortized Debt Issuance Costs	296.8	311.3
Debt Instrument, Unamortized Discount	0.0	0.0
Long-term Debt, Fair Value	275.1	277.9
2021 Secured Railcar Equipment Notes [Domain] | Wholly Owned Subsidiaries [Member] | Railcar Leasing and Services Group [Member]
Debt Instrument [Line Items]
Debt, Net of Unamortized Discount and Premium, Gross of Unamortized Debt Issuance Costs	706.4	295.3
Debt Instrument, Unamortized Discount	(0.1)	0.0
Long-term Debt, Fair Value	682.5	256.9
2022 Secured Railcar Equipment Notes [Domain] | Wholly Owned Subsidiaries [Member] | Railcar Leasing and Services Group [Member]
Debt Instrument [Line Items]
Debt, Net of Unamortized Discount and Premium, Gross of Unamortized Debt Issuance Costs	223.7	232.7
Debt Instrument, Unamortized Discount	0.0	0.0
Long-term Debt, Fair Value	215.8	220.2
Other Equipment Financing | Wholly Owned Subsidiaries [Member] | Railcar Leasing and Services Group [Member]
Debt Instrument [Line Items]
Secured Debt, Other	50.0	52.3
Long-term Debt, Fair Value	50.0	52.3
TRP 2021 Secured Railcar Equipment Notes - RIV 2013 [Member] | Partially-Owned Subsidiaries [Member] | Railcar Leasing and Services Group [Member]
Debt Instrument [Line Items]
Debt, Net of Unamortized Discount and Premium, Gross of Unamortized Debt Issuance Costs	319.6	335.1
Debt Instrument, Unamortized Discount	0.0	0.0
Long-term Debt, Fair Value	296.9	296.3
Triumph Secured Railcar Equipment Notes [Member] | Partially-Owned Subsidiaries [Member] | Railcar Leasing and Services Group [Member]
Debt Instrument [Line Items]
Debt, Net of Unamortized Discount and Premium, Gross of Unamortized Debt Issuance Costs	469.4	501.7
Debt Instrument, Unamortized Discount	(0.1)	(0.1)
Long-term Debt, Fair Value	437.1	447.6
Tribute Secured Railcar Equipment Notes | Partially-Owned Subsidiaries [Member] | Railcar Leasing and Services Group [Member]
Debt Instrument [Line Items]
Debt, Net of Unamortized Discount and Premium, Gross of Unamortized Debt Issuance Costs	287.8	311.0
Debt Instrument, Unamortized Discount	0.0	0.0
Long-term Debt, Fair Value	285.0	300.1
Line of Credit [Member] | TRL-2023 Term Loan | Wholly Owned Subsidiaries [Member] | Railcar Leasing and Services Group [Member]
Debt Instrument [Line Items]
Long-term Line of Credit	323.4	334.5
Long-term Debt, Fair Value	323.4	334.5
4.55% Senior Notes Due October 2024 [Member] | Corporate Segment [Member]
Debt Instrument [Line Items]
Senior Notes	0.0	399.9
Debt Instrument, Unamortized Discount	0.0	(0.1)
Long-term Debt, Fair Value	0.0	394.5
7.75% Senior Notes Due 2028 | Corporate Segment [Member]
Debt Instrument [Line Items]
Senior Notes	604.3	400.0
Debt Instrument, Unamortized Premium	4.3	0.0
Long-term Debt, Fair Value	623.2	417.6
Promissory Notes [Member] | 2017 Secured Railcar Equipment Notes [Domain] | Wholly Owned Subsidiaries [Member] | Railcar Leasing and Services Group [Member]
Debt Instrument [Line Items]
Debt, Net of Unamortized Discount and Premium, Gross of Unamortized Debt Issuance Costs	631.3	673.7
Debt Instrument, Unamortized Discount	(1.5)	(3.5)
Non-Recourse Debt, Gross	632.8
Long-term Debt, Fair Value	631.3	673.7
Revolving Credit Facility [Member] | Line of Credit [Member] | Corporate Segment [Member]
Debt Instrument [Line Items]
Long-term Line of Credit	0.0	0.0
Long-term Debt, Fair Value	0.0	0.0
Revolving Credit Facility [Member] | Line of Credit [Member] | TILC Warehouse Facility [Member] | TILC [Member] | Railcar Leasing and Services Group [Member]
Debt Instrument [Line Items]
Long-term Line of Credit	584.6	529.3
Long-term Debt, Fair Value	$ 584.6	$ 529.3